Background: Timing intercourse is important. Traditional methods for fertile window calculation utilizing luteinizing hormone (LH) strips and tracking are not user-friendly: those methods are not integrated in a single platform. This leads to a misreading of the LH test result and a complex calculation/ tracking of the fertile windows for women, therefore, we simplify the procedure and ease off the stress in women in order to maximize their chances to conceive naturally. The new method: An innovative approach to monitor LH levels in urine during the fertile window to increase the conception chances. Eveline Smart Fertility System provides a clear, clever and complete solution for the women who are trying to conceive. It is a smartphone-based platform, which combines ovulation test analysis, menstrual cycle tracking, fertile window prediction and the relevant in-time notification as well as recordings. Users can also share a real-time data to better plan their intercourse. Performance: The accuracy report related to the Eveline Test Strip shows the sensitivity, specificity and accuracy above 95%. Moreover, the accuracy report of Eveline Smart Fertility System (Eveline Ovulation Test Strip + Eveline Application) shows a good performance with over 96% accuracy on the ovulation test analysis, menstrual cycle tracking, fertile window prediction. Conclusion: With the smartphone-based high accuracy digital analysis, three seconds automatic recording, menstrual cycle tracking, and fertile window prediction, Eveline Smart Fertility System helps women to identify the right time for intercourse. On the other hand, it enables users to have a few months comprehensive understanding of their menstrual cycles and ovulations before visiting gynaecologists, fertility centres or in-vitro fertilisation centres.